This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 09-313944, filed Nov. 14, 1997; No. 09-313945, filed Nov. 14, 1997; and No. 09-313946, filed Nov. 14, 1997, the entire contents of which are incorporated herein by reference.
The present invention relates to a smart card having both a function of a contact type in which reception of supply power, transmission/reception of signals, etc. are performed via an electrical contact, and a function of a non-contact type in which reception of supply power, transmission/reception of signals, etc. are performed without provision of an electrical contact, in an information recording medium represented by IC cards, etc. used in fields such as office automation (OA), factory automation (FA) or security. The present invention also relates to an IC module used for the smart card.
With the advent of IC cards including semiconductor memories, etc., information recording media with greatly increased memory capacities, compared to conventional magnetic cards, etc., have been realized. In addition, with internal provision of a semiconductor integrated circuit device such as a microcomputer, an IC card itself has an arithmetic process function and this provides high security to the information recording medium.
The IC cards are internationally standardized by the ISO (International Organization for Standardization). In general, in an IC card, an IC such as a semiconductor memory is built in a card body formed of a plastic material as a basic material and metallic conductive terminal electrodes are provided on a card surface for connection with an external read/write apparatus. In order to effect data communication between the IC card and external read/write apparatus, the IC card is inserted in a card slot of the external read/write apparatus and the terminal electrodes of the IC card are connected to the external read/write apparatus.
This is suitable for uses requiring security and safety for communication as in large-volume data exchange and banking processing, for example, uses for crediting and electronic wallets.
On the other hand, when the IC card is applied to gate management for entrance/exit, etc., the main purpose for communication is identification and in most cases the amount of communication data is small. Accordingly, simple processing is desired. To solve this problem, a non-contact type IC card has been devised.
With this type of IC card, an oscillation energy field of high-frequency electromagnetism, ultrasonics, light, etc. is provided in the space. The energy is absorbed and converted to an AC power. The AC power is rectified to a DC source for driving an electronic circuit provided in the card. The frequency of an AC component in the field may be used as it is, or multiplied or divided to produce an identification signal. The identification signal is transmitted as data to an information processing circuit formed of a semiconductor device via a coupler such as an antenna coil or a capacitive element.
In particular, most of non-contact type IC cards designed for identification or simple numerical data processing are associated with Radio Frequency Identification (RF-ID) of a hard logic which does not have a battery cell and a CPU (Central Processing Unit). With the advent of the non-contact type IC card, safety from forgery or falsification is enhanced, compared with magnetic cards. Moreover, when a carrier of the card passes through a gate, it should suffice if the carrier approaches the card to an antenna unit of the read/write apparatus attached to the gate apparatus or brings the card into contact with the antenna unit of the read/write apparatus. The carrier does not have to do time-consuming operations of taking the card out of the case and inserting it in the slot in the read/write apparatus.
Recently, in order to apply a single card to many purposes, a smart card has been devised which has the former contact type function with external terminals and the latter non-contact type function with radio-frequency data communication. This smart card has advantages of both types, i.e. high security of the contact type which is realized by CPU processing and convenience of the non-contact type. In either the non-contact type or the composite type, where a power supply is provided in the IC card, there is no need to obtain power from the aforementioned oscillation energy field in the space.
A general mounting method for the smart card will be described blow.
A metallic foil antenna coil for non-contact transmission, which is formed by etching, is sandwiched between a sheet with engagement hole for an IC module and a substrate. The structure is laminated to produce a card body. In this case, two antenna terminals for connection between the antenna coil and the IC module are exposed to an inside of the engagement hole in the card body.
Metallic terminal electrodes for connection with an external apparatus are provided on one surface of the IC module. The other surface is provided with an IC and terminals for connection with the antenna. A conductive adhesive is applied to the terminals. The IC module is mounted in the engagement hole in the card body such that the terminals with the conductive adhesive may overlap the antenna terminals of the card, and then the terminals of the IC module are connected to the antenna terminals with heat and pressure. Thus, the mounting is completed.
This mounting method is relatively simple. However, it is difficult to confirm the state of the connection portion between the IC module and antenna, and a problem remains with the reliability of connection. In addition, degradation in the connection portion may easily occur due to mechanical stress. Moreover, since a step for applying the conductive adhesive and a thermocompression step are required for the connection between the IC module and antenna, it is difficult to use an apparatus for manufacturing a conventional IC card with external terminals. It is thus necessary to provide a new manufacturing line.
In addition, in most of IC cards with the non-contact-type transmission mechanism, an emboss or a magnetic stripe cannot be applied due to restrictions of the coil shape, etc. for keeping reception power. In order to fully meet a demand on the market, the emboss and magnetic stripe have to be considered. Techniques which do not permit provision of an emboss or a magnetic stripe are restricted in the range of application.
A non-contact-type IC card disclosed, for example, in Jpn. Pat. Appln. KOKAI Publication No. 8-227,447 permits provision of an emboss and a magnetic stripe. Specifically, a non-contact-type IC card having an outer shape according to ISO 7811 is provided. In order to provide a magnetic stripe and an emboss on the card, a communication IC module is constructed such that an IC mount portion, a power receiving coil and a data transmission/reception coil are arranged in a longitudinal direction on a region excluding the magnetic stripe region and embossing region.
The reception coil and communication coil of the communication IC module are comprised of single-layer coils formed by electrocasting. Both are buried in a single strip-like substrate. Lead portions for connection with pads of the IC chip are formed of each coil.
The IC chip is mounted on the strip-like substrate such that a circuit surface of the IC chip is opposed to the strip-like substrate. The lead portions are bump-bonded to the IC pads and a gap between the strip-like substrate and IC chip is filled with a potting resin for fixation. An inner end portion of the coil and an end portion of an internal-end lead are jumper-bonded by an enamel copper wire. The bonding is effected by instantaneous thermocompression and terminal portions are protected with potting resin.
A method of integrating this communication IC module and the card is described. According to this method, there are provided a first sheet for covering the upper surface, a second sheet having the same thickness as the strip-like substrate and having a window with a strip-like outer shape, a third sheet having a window for passing the IC chip and a window for passing a first jumper-bonding portion, a fourth sheet having only a window for passing the IC chip, and a fifth sheet for covering the lower surface (all formed of vinyl chloride). The communication module is sandwiched by the respective sheets and subjected to thermocompression. Thus, the communication module is integrated in the card.
Although the above technique is applicable to the non-contact-type IC card, it is not applicable to the smart card having external terminals.
The positions of the terminals of the card with external terminals are specified by ISO 7816. FIG. 1 shows a magnetic stripe region, an embossing region and an external terminal region specified by ISO 7816. In the smart card, an IC module is mounted on the external terminal region. In FIG. 1, in the regions indicated by hatching, mounting of an antenna for non-contact coupling is prohibited.
ISO 7816 specifies an outer long side to be 85.47-85.72 mm, an outer short side to be 53.29-54.03 mm. The magnetic stripe region is defined in an area of 15.82 mm from the upper side. The embossing region is defined in an area of 24 mm from the lower side, 6.0 mm from the left side, and 8.0 mm from the right side. The external terminals are formed in an area of 28.55 mm from the upper side and 19.87 mm from the left side.
For example, Jpn. Pat. Appln. KOKAI Publication No. 7-239,922 discloses a prior-art technique of a smart card realizing a magnetic stripe and embossing.
According to this technique, the IC module for the IC card comprises an IC chip; a transmission mechanism connected to the IC chip for effecting transmission of information and/or power with the external apparatus; and a support member for supporting the IC chip and transmission mechanism. The transmission mechanism comprises a non-contact-type transmission mechanism having a coil or an antenna, and a contact-type transmission mechanism having a plurality of terminal electrodes of patterned conductors provided on a surface of the support member. This document teaches that since the functions compatible with the contact type and non-contact type are constructed as a module and this IC module is fitted and fixed in a plastic card body, the magnetic stripe and embossing can be made without hindrance.
The document further discloses, as mounting means, that the antenna or coil for non-contact transmission is provided so as to surround the terminal electrodes, and alternatively the antenna is positioned at the center and the terminal electrodes are provided around the antenna.
Specifically, the non-contact transmission antenna is contained in the IC module and thereby the connection between the antenna coil and the IC module is omitted in the final step.
In view of the standard illustrated in FIG. 1, however, it is clear that the method in which the antenna coil is provided around the terminal electrodes is not feasible. More specifically, in the method in which the non-contact transmission antenna is contained in the IC module, an adequate antenna area is not obtained, and this permits only a so-called close-contact mode in which the distance for communication is several mm or less.
Since the distance between the terminal electrodes and embossing region is 1.45 mm at maximum, it is not practical to dispose the antenna or coil so as to surround the terminal electrodes without overlapping the terminal electrodes, as will be described below. In the case where the antenna coil is disposed around the external terminals, the maximum outside diameter and minimum inside diameter of the coil are xcfx8612 mm and xcfx869.3 mm, respectively. If the antenna coil is formed of a print pattern in this region, where the pattern width and interval are 0.15 mm and 0.1 mm respectively, the number of turns and the inductance become about four and 0.4 xcexcH, and six and 1.0 xcexcH in respective cases (xcexcH denotes microhenry). Where the coil is disposed around the outer periphery of the terminal electrodes while the embossing region maintained, only several turns are obtained even with the formation of the print coil. Owing to the smallness of the area of the coil, too, adequate power cannot be obtained and only close coupling is permitted with a communication distance being several mm or less.
In this case, the merit of adding the non-contact transmission function is small. The merit of adding the non-contact transmission mechanism to the contact type transmission mechanism is obtained with a communication distance exceeding several-ten mm to 100 mm. Communication is achieved if the card is exposed to the antenna unit of the external read/write apparatus within such an area. For this purpose, it is necessary to increase the area of the coil or the number of turns.
In brief, where the coil is disposed around the outer periphery of the terminal electrodes within the IC module, only several turns are obtained even if the print coil is formed, and owing to the smallness of the area of the coil, too, adequate power cannot be obtained. Moreover, if a practical number of turns is to be obtained with a conductor pattern, it overlaps the embossing region.
On the other hand, in the case of the latter mounting means wherein the terminal electrodes are disposed around the antenna, the embossing area is obviously occupied and the standard of the IC card with external terminals, ISO 7816, is not at all satisfied. The likelihood of acceptance in the market is very low.
Since the smart card is associated with weak radio waves, there is a demand to enhance power transmission efficiency. Prior-art techniques for this purpose are described, for example, in Jpn. Pat. Appln. KOKAI Publication No. 2-7,838 and Jpn. Pat. Appln. KOKAI Publication No. 63-224,635. In these prior-art methods for enhancing the power transmission efficiency, however, attention is paid only to transmission power and these methods are effective only in cases where the transmission-side power efficiency can be improved and more power be sent out. Consequently, where the intensity of a radiant electromagnetic field is limited, these methods do not contribute to the improvement in the reception-side power reception efficiency. In order to improve the power reception performance of the smart card located in a weak electromagnetic field with the non-contact type function of the IC card itself, it is necessary to provide the card with means for absorbing more radiation energy.
Furthermore, since the smart card includes a semiconductor integrated circuit, acquisition of more current with less power is desirable for reduction of a load on the power supply circuit. In order words, it is desirable to lower the power-reception side impedance. In the prior art, however, attention is paid only to the transmission voltage and not to the power reception side.
A first object of the present invention is to overcome the problems in the prior art and provide an IC module having reception sensitivity enough to obtain an adequate communication distance, despite no wired connection disposed between the IC module and a non-contact transmission antenna, and being capable of maintaining both a contact-type and a non-contact-type transmission mechanism in practical operation states, and to provide a smart card including the IC module.
A second object of the present invention is provide a smart card having both functions of contact type and non-contact type and being capable of performing at least either of power reception or signal transmission/reception in a non-contact mode, wherein the carrier wave reception efficiency on the smart card side is enhanced by a coupler in which a power transmission side (reader/writer side) coil is separated from a power reception side (smart card side) antenna with an air gap, thereby improving power efficiency on the power reception side (or signal transmission efficiency) and performing impedance conversion, and to provide an IC module for the smart card.
A third object of the invention is to provide an IC module and a smart card having both a contact-type transmission mechanism and a non-contact-type transmission mechanism and having a magnetic stripe and an embossed portion on a surface of the card, wherein power-reception-side power efficiency is improved and impedance conversion is effected without adversely affecting formation of the magnetic stripe and embossed portion and the thickness of the card can be reduced.
(1) A smart card according to the present invention has both a function of a contact type and a function of a non-contact type, the smart card comprising an IC module and an antenna element. The IC module comprises an IC chip incorporating a contact-type transmission function and a non-contact-type transmission function, and a module substrate having an external terminal serving as a contact-type transmission element and a first coupler coil. The antenna element comprises an antenna for performing at least one of power reception and signal transmission/reception with an external read/write apparatus, and a second coupler coil connected to the antenna. The first coupler coil of the IC module and the second coupler coil of the antenna element for non-contact transmission are disposed to be closely coupled to each other, and the IC module and the antenna element are coupled in a non-contact manner by transformer coupling.
(2) According to the invention, in the smart card described in (1), the antenna element has a capacitive element.
(3) According to the invention, the smart card described in (1) or (2) further comprises an embossing region. The IC module is provided at a substantially central portion of one shorter side of the card, and the embossing region is provided along one longer side of the card. The antenna for non-contact transmission is provided so as not to interfere with an external terminal region of the IC module and the embossing region.
(4) According to the invention, the smart card described in (1) or (2) further comprises an embossing region. The IC module is provided at a substantially central portion of one shorter side of the card, and the embossing region is provided along one longer side of the card. The antenna for non-contact transmission is provided so as not to interfere with an external terminal region of the IC module and the embossing region. The antenna is provided at a region defined by a longer side of the card opposed to the one longer side along which the embossing region is provided, a boundary of the embossing region on an inner side of the card, a boundary of the external terminal region of the IC module on the inner side of the card, and a shorter side of the card opposed to the one shorter side at which the IC module is provided.
(5) According to the invention, the smart card described in (1) or (2) further comprises an embossing region. The IC module is provided at a substantially central portion of one shorter side of the card, and the embossing region is provided along one longer side of the card. At least a portion of the antenna for non-contact transmission is disposed between the embossing region and an edge of the card and between an external terminal region of the IC module and an edge of the card, and along a periphery of the card so as not to interfere with the external terminal region of the IC module and the embossing region.
(6) According to the invention, the smart card described in (1) or (2) further comprises a magnetic stripe region and an embossing region. The IC module is provided at a substantially central portion of one shorter side of the card, the embossing region is provided along one longer side of the card, and the magnetic stripe region is provided along the other longer side of the card. The antenna for non-contact transmission is provided so as not to interfere with an external terminal region of the IC module, the embossing region, and the magnetic stripe region.
(7) According to the invention, the smart card described in (1) or (2) further comprises a magnetic stripe region and an embossing region. The IC module is provided at a substantially central portion of one shorter side of the card, the embossing region is provided along one longer side of the card, and the magnetic stripe region is provided along the other longer side of the card. The antenna for non-contact transmission is provided substantially along a boundary of the magnetic stripe region on an inner side of the card, a boundary of the embossing region on an outer peripheral side of the card, and a boundary of an external terminal region of the IC module on the outer peripheral side of the card, so as not to interfere with an external terminal region of the IC module, the embossing region, and the magnetic stripe region.
(8) According to the invention, the smart card described in (1) or (2) further comprises a magnetic stripe region and an embossing region. The IC module is provided at a substantially central portion of one shorter side of the card, the embossing region is provided along one longer side of the card, and the magnetic stripe region is provided along the other longer side of the card. The antenna for non-contact transmission is provided at a region defined by a boundary of the embossing region on an inner side of the card, a boundary of an external terminal region of the IC module on the inner side of the card, a boundary of the magnetic stripe region on the inner side of the card and a shorter side opposed to the one shorter side at which the IC module is provided, so as not to interfere with an external terminal region of the IC module, the embossing region, and the magnetic stripe region.
(9) According to the invention, in the smart card described in (1) or (2), the second coupler coil of the antenna element is disposed outside a loop of the antenna.
(10) An IC module according to the present invention comprises an IC chip incorporating a non-contact-type transmission function and a contact-type transmission function, and a module substrate having a first coupler coil and an external terminal serving as a contact-type transmission element. The first coupler coil is provided on a side of the module substrate which is opposite to a side on which the external terminal is provided, and is formed of a winding coil fabricated by winding conductor wire coated with an insulation film.
(11) According to the invention, in the IC module described in (10), the winding coil is spirally wound on at least one of a periphery and a vicinity of the IC chip.
(12) According to the invention, in the IC module described in (10), the winding coil is toroidally wound on at least one of a periphery and a vicinity of the IC chip.
(13) According to the invention, in the IC module described in (10), the winding coil is wound around an outer peripheral end face of the module substrate.
(14) According to the invention, in the IC module described in any one of (10) to (13), the IC chip and the first coupler coil are resin-sealed on a side of the IC module on which the IC chip is mounted.
(15) According to the invention, in the IC module described in any one of (10) to (13), a size of the module substrate is substantially equal to a size of a region of the external terminal.
(16) An IC module according to the present invention comprises an IC chip incorporating a contact-type transmission function and a non-contact-type transmission function, and a module substrate having a first coupler coil and an external terminal serving as a contact-type transmission element. The first coupler coil is formed of a patterned conductor on a side of the module substrate which is opposite to a side on which the external terminal is provided, and is disposed on at least one of a periphery and a vicinity of the IC chip.
(17) According to the invention, in the IC module described in (16), the coil is wound around a seal member of the IC chip in at least one of a spiral manner and a toroidal manner.
(18) According to the invention, in the IC module described in (16), the IC chip and the first coupler coil are resin-sealed on a side of the IC module on which the IC chip is mounted.
(19) According to the invention, in the IC module described in (16), a size of the module substrate is substantially equal to a size of a region of the external terminal.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.